[PATCH 07/13] nvme-pci: don't poll from irq context when deleting queues

[Christoph Hellwig]

This is the last place outside of nvme_irq that handles CQEs from
interrupt context, and thus is in the way of removing the cq_lock for
normal queues, and avoiding lockdep warnings on the poll queues, for
which we already take it without IRQ disabling.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 drivers/nvme/host/pci.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 29072ad0a268..ef10279f4e58 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -202,6 +202,7 @@ struct nvme_queue {
        unsigned long flags;
 #define NVMEQ_ENABLED          0
 #define NVMEQ_SQ_CMB           1
+#define NVMEQ_DELETE_ERROR     2
        u32 *dbbuf_sq_db;
        u32 *dbbuf_cq_db;
        u32 *dbbuf_sq_ei;
@@ -2185,7 +2186,7 @@ static void nvme_del_cq_end(struct request *req, 
blk_status_t error)
        struct nvme_queue *nvmeq = req->end_io_data;
 
        if (!error)
-               nvme_poll_irqdisable(nvmeq, -1);
+               set_bit(NVMEQ_DELETE_ERROR, &nvmeq->flags);
 
        nvme_del_queue_end(req, error);
 }
@@ -2227,11 +2228,20 @@ static bool nvme_disable_io_queues(struct nvme_dev 
*dev, u8 opcode)
                nr_queues--;
                sent++;
        }
-       while (sent--) {
+       while (sent) {
+               struct nvme_queue *nvmeq = &dev->queues[nr_queues + sent];
+
                timeout = wait_for_completion_io_timeout(&dev->ioq_wait,
                                timeout);
                if (timeout == 0)
                        return false;
+
+               /* handle any remaining CQEs */
+               if (opcode == nvme_admin_delete_cq &&
+                   !test_bit(NVMEQ_DELETE_ERROR, &nvmeq->flags))
+                       nvme_poll_irqdisable(nvmeq, -1);
+
+               sent--;
                if (nr_queues)
                        goto retry;
        }
-- 
2.19.1